Switching the European economy to renewable energy over the next 50 years

by Olav Hohmeyer, professor of economics at the University of Flensburg

According to a German study, it is possible for the European economy to phase out the use of both nuclear energy and fossil fuels by 2050 while maintaining living standards. Doing this, however, requires decisions to be taken now, so that future energy demands are minimised.


Emissions of carbon dioxide account for about 55% of the human influence on the greenhouse effect (Loske 1996) and most of these emissions come from energy conversion processes. If the Intergovernmental Panel on Climate Change (IPCC) is right and the anthropogenic greenhouse effect is real (see IPCC 2001, p. 4), greenhouse gas (GHG) emissions need to be reduced enough to restrict long term global surface temperature changes to less than 30C (see IPCC 2001, p. 22).

This is especially true for CO2 emissions, the main cause of the problem. The IPCC scenarios show that if CO2 concentrations are to be stablised at 450 parts per million (ppmv), a level that ought to limit temperature change to less than 30C, the present emission level of 8 gigatonnes of carbon a year (Gt C/a) would have to be reduced by about half by 2050 and to about 1 Gt C/a by the year 2200. As WRE450, the lowest line in Figure 2C1 (a), shows, emissions of CO2 would need to peak within 10 to 15 years from now to allow a transition to an emission pathway leading to a long term concentration of approximately 450 ppmv.

(Source: IPCC 2001, p.20)

Because the CO2 emissions from energy conversion processes are caused by the combustion of fossil fuels, the use of these fuels has to be reduced massively within the next fifty years. Industrialised nations have contributed most of the past increase in GHG concentrations in the atmosphere, so the United Nations Framework Convention on Climate Change (UNFCCC) assumes that these countries will take special steps (UNFCCC Article 4) to prevent dangerous interferences with the global climate. The German Parliament's first commission on global climate change concluded that industrialised countries should reduce their GHG emissions to 20% of their 1990 emission level by 2050 (Deutscher Bundestag 1991, p. 867). See Figure 2C2. This 80% cut means that the use of fossil fuels has to be reduced accordingly.

Since the reactor accident at Chernobyl there has been serious doubt whether nuclear power can safely replace fossil fuels for energy generation to the extent required to achieve this level of reduction of GHG emissions. In countries like Germany, Austria, Sweden or Denmark there is massive resistance in the population to even the modest use of nuclear power. Moreover, as the uranium resources available seem to be as limited as our reserves of oil and natural gas, and since the problem of very long term storage of spent nuclear fuel has not yet been solved, it seems to be rather unlikely that a future energy system will primarily be based on nuclear energy.

If we accept these two assumptions, a future sustainable energy system has to be based on renewable energy sources. Considering that the Earth will provide us with suitable living conditions in the solar system for something like 800 million years, that the internal resources of the planet are definitely limited by its physical size, and that the only resource income from outside the planet is solar radiation, it is quite obvious that this outside energy income will be the only long term energy source for a sustainable energy supply. Knowing the solar energy income is about 3.5*106 EJ/a and the anthropogenic world energy consumption of 1999 was about 406 EJ/a (see BMWi 2002, p. 39) it is quite obvious that the amount of direct and indirect solar energy available will be sufficient to cover the energy needs of mankind for all the time this planet will be habitable. The remaining lifetime of the sun is estimated to be about 5 billion years. Thus, there will certainly be sufficient solar energy available for the entire time that human beings may live on this planet.

Renewable energy sources are used to only a limited extent at present. They provided only 3.2% of the world consumption of commercial fuels in 1998 (Fischer 2002, table on world energy consumption). This limited use is due to the relatively high internal costs of the use of renewable energy sources. As energy markets do not take into account the external cost of the environmental and health damage caused by the use of fossil fuels or nuclear energy, investors choose to develop conventional rather than renewable energy sources (see e.g. Hohmeyer 1988, p. 108f). Thus, a transition to a renewable energy based sustainable energy system will need a policy framework that internalises the long term external costs of all energy sources including long term impacts on global climate change.

As renewable energy sources will be relatively expensive compared with present conventional ones, future energy systems can be expected to use energy far more efficiently. What would such an energy system look like and could the transition to it be possible within the time frame set by the necessity to avert a catastrophic global climate change?


In 1993, a European research consortium, the LTI-Research Group, reported on what might be involved if the fifteen countries that were then members of the EU, the EU15, attempted to develop a sustainable, renewables-based energy system by 2050. Would it be possible to phase out nuclear energy while at the same time reducing CO2 emissions by 80%? (LTIResearch Group, 1998, p.1). Most of the rest of this paper is based on the results of the LTI project.


As the LTI project had a broad perspective on sustainable development, some basic assumptions were made beyond the energy system. The most important of these were: